Transfusion tissue thin walled cells between vascular

Transfusion Tissue
- Thin walled cells
- Between vascular
tissue and
endodermis
- Mesophyll
- Not divided into
spongy and palisade
layer
- Found in fascicles (bundles)
- 1st produced - Joined closely to one
another within fascicle
- As they grow → Spread out from other
members of fascicle to produce fan-like
spread of leaves
- Fascicles
- Can contain 2-5 leaves

Pine Reproduction
- Produce 2 types of cones :
- Seed Cones
- Pollen Cones
** Often produced on same plant, but some
species are DIOECIOUS - one plant producing
seed cones and the other pollen cones.
Pollen Cones
- Composed of thin, papery scales attached
to central cone axis
- No bracts are involved
- Smaller than seed cones
- Consists of sporophylls
- Sporophylls
- Directly attached to cone axis
- Supports sporangia
- Sporangia
- Has numerous
microsporocytes
- Microsporocytes
- Undergo meiosis
- Produce microspores
- Microspores
- Divide by mitosis
- Form an immature male
gametophyte
- Pollen Grain
- Male gametophyte
- Released from pollen tubes
into the air
- Circulate with air currents
- Some are carried to ovule
of seed cone
- Has 2 air bladders
- Air Bladders
- Provide buoyancy in
air
- Composed of 4 cells in the
center area
1. Generative Cell
- Produces 2 sperm cell
2. Tube Cell
- Elongates to form pollen
tube
- Pollen Tube
- Produced upon a
pollen grain arriving
in an ovule
- Digests its way
through the nucellus
and the female
gametophyte, into
an archegonium and
delivers sperm to
the egg for
fertilization
3. Body Cell
4. Body Cell
-
Gymnosperms and other seed plants produce
ovules.

Ovules
- Found in pairs
- produced on surfaces of ovuliferous
scales
- Ovuliferous scales
- Composed of bracts (which
contain additional buds)
- Attached to one central cone axis
- Ovules are found at base
- Base : where ovules attach to axis
- Bracts
- Branch off the central cone axis
- Supports a bud that gives rise to
sporophyll
- Fuse with sporophylls to form
ovuliferous scale
- Bound by a integument
- Integument
- Protective wall of ovules
- Houses the ff:
- megasporangium
- megaspore
- female gametophyte
- Eggs
- After fertilized, integument
hardens to form seed coat
- Embryo develops within ovule
- Entire structure is called SEED
- Seed
- Released when mature
- Germinate when reach soil in
suitable habitat
- Micropyle
- Opening of ovules in one end
- Where pollen grains enter during
pollination
- Nucellus
- Remnants of microsporangium
- Where pollen grains rest
Seed Cone
- Female Pine cones
- Large
- Woody
Process:
e-cycle.html
1. Ovules are produced
2.